[MSVC] Bitcoin failed to build with waring c4858 on MSVC #26017

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Describe Hi all, Bitcoin fails to build on MSVC due to waring c4858. Could you help look? Expected behavior Build successfully.

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Actual behavior F:\gitP\bitcoin\bitcoin\src\sync.h(168): error C2220: the following warning is treated as an error F:\gitP\bitcoin\bitcoin\src\sync.h(166): note: while compiling class template member function 'bool UniqueLock<_Ty,std::unique_lock<PARENT>>::TryEnter(const char *,const char *,int)' with [ _Ty=RecursiveMutex, PARENT=std::recursive_mutex ] F:\gitP\bitcoin\bitcoin\src\sync.h(179): note: see reference to function template instantiation 'bool UniqueLock<_Ty,std::unique_lock<PARENT>>::TryEnter(const char *,const char *,int)' being compiled with [ _Ty=RecursiveMutex, PARENT=std::recursive_mutex ] F:\gitP\bitcoin\bitcoin\src\net.h(822): note: see reference to class template instantiation 'UniqueLock<_Ty,std::unique_lock<PARENT>>' being compiled with [ _Ty=RecursiveMutex, PARENT=std::recursive_mutex ] F:\gitP\bitcoin\bitcoin\src\sync.h(168): warning C4858: discarding return value: This function returns whether the operation succeeded in modifying object state. It is dangerous to ignore the return value. Detail log Uploading build (3).log…

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To reproduce

1. git clone https://github.com/bitcoin/bitcoin F:\gitP\bitcoin\bitcoin
2. cd F:\gitP\bitcoin\bitcoin\build_msvc
3. py -3 msvc-autogen.py
4. cd F:\gitP\bitcoin\tools\vcpkg
5. git -C "F:\gitP\bitcoin\tools\vcpkg" clean -xdf 2>&1
6. bootstrap-vcpkg.bat 2>&1
7. set path=%cd%;%path%
8. cd F:\gitP\bitcoin\bitcoin\build_msvc
9. msbuild /m /p:Platform=x64 /p:Configuration=Release bitcoin.sln /t:Rebuild 2>&1

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System information VS version: VS2019 (16.11.11) Operating system: windows server 2019 the commit of Bitcoin we use is 5174a13

workaround I modified the common.init.vcxproj.in file of this text like below to solve this issue: <DisableSpecificWarnings>4018;4244;4267;4334;4715;4805;4834</DisableSpecificWarnings> to be: <DisableSpecificWarnings>4018;4244;4267;4334;4715;4805;4834;4858</DisableSpecificWarnings>

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VS version: VS2019 (16.11.11)

Visual Studio 2022 is minimum required to build Bitcoin Core.

This is an internal test of MSVC, using the latest compiler

This is an internal test of MSVC, using the latest compiler

Which version? In any case, bugs in internal tests against msvc should likely be reported to microsoft.

F:\gitP\bitcoin\bitcoin\src\sync.h(168): warning C4858: discarding return value: This function returns whether the operation succeeded in modifying object state. It is dangerous to ignore the return value.

Microsoft's docs do not mention "C4858", but "C4834", which is fixed in #25819.

Which version? In any case, bugs in internal tests against msvc should likely be reported to microsoft.

The version used is as follows：

@fangzhouxia Would you mind testing https://github.com/bitcoin/bitcoin/pull/25819/commits/31168dd9b823573c7941adf27d24f6ece98cf5ea?

OK, I will try using this https://github.com/bitcoin/bitcoin/commit/31168dd9b823573c7941adf27d24f6ece98cf5ea

Thank you, I use the method you provided, it is ok.